A sheet of this kind is applied in order to achieve better sound insulation, in particular better footstep and room sound insulation.
A foamed sheet is preferably used for this purpose.
Normally, this sheet is either laid loosely or is fixed to the base by means of an adhesive applied over the entire underside.
The floor boards or tiles, which may, for example, comprise parquet blocks or laminated floor, can then be placed loosely on the sheet and connected to one another, for example in the form of tongue-and-groove connections.
However, cavities may form in regions beneath the floor laid in this manner, either due to unevenness of the base or due to distortion of the floor boards, so that no footstep sound insulation is provided in these regions.
This manifests itself acoustically by clicking noises when the floor is walked on.
Noise of this kind is considered extremely disruptive, in particular in tenement blocks, since the occupants of adjacent flats are also affected as a result.